Generally, in a magnetic resonance imaging apparatus, a great number of coil units are connectable to a control unit due to increased channels of a collection system. Accordingly, the number of connecting cables between the coil units and the control unit is inconveniently increased. It is therefore desired to wirelessly transmit signals between the coil units and the control unit.
Under these circumstances, there has already been suggested a technique that enables wireless signal transmission between a coil unit and a control unit (e.g., see Jpn. Pat. Appln. KOKAI Publication No. 05-261085). A related technique is also disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2001-76439.
Recent coil units have an increasing number of functions, and the operating condition of the coil unit has to be controllable from the control unit. If a control signal used for this purpose is also wirelessly transmitted, there is a further increase of radio channels.
In the meantime, the present applicant has suggested, as Jpn. Pat. Appln. No. 2009-122247 (Jpn. Pat. Appln. KOKAI Publication No. 2010-29644), a technique that uses a digital wireless method for the signal transmission between a coil unit and a control unit (main unit). According to this technique suggested in Jpn. Pat. Appln. No. 2009-122247, radio channels for respectively transmitting a sampling clock and a carrier wave are required.
Thus, disadvantageously, a great number of radio channels are needed for the signal transmission between the coil units and the control unit, and the scale of a circuit for sending/receiving radio signals is increased.
Consequently, there has been a desire to reduce the number of radio channels so that the scale of the circuit for sending/receiving radio signals can be reduced.